Water Intake Calculator
Estimate your recommended daily water intake based on your body weight, exercise level, and climate, right in your browser. Includes adjustments for pregnancy and breastfeeding. Nothing is sent to a server.
Weight-based baseline
Uses a common clinical guideline of roughly 33 mL of water per kilogram of body weight as the starting baseline.
Activity and climate adjustments
Adds extra water for exercise minutes per day, and scales up further for hot, humid, or high-altitude climates where fluid loss is greater.
Pregnancy and breastfeeding
Optional adjustments add the additional recommended fluid intake for pregnancy or breastfeeding.
Common Mistakes to Avoid
Ignoring climate and exercise
Solution:
Fluid needs rise significantly with heat and physical activity — always adjust for both rather than using a flat "8 glasses a day" rule.
Treating this as medical advice
Solution:
This is a general estimate — people with certain health conditions (like kidney or heart issues) should follow their doctor's specific fluid guidance instead.
Frequently Asked Questions
This calculator estimates plain water intake specifically; other fluids contribute too, but water remains the best default source.
No — that's a rough general rule. Actual needs vary a lot by body weight, activity level, and climate, which is why this calculator personalizes the estimate.
Weight-based baseline
Uses a common clinical guideline of roughly 33 mL of water per kilogram of body weight as the starting baseline.
Activity and climate adjustments
Adds extra water for exercise minutes per day, and scales up further for hot, humid, or high-altitude climates where fluid loss is greater.
Pregnancy and breastfeeding
Optional adjustments add the additional recommended fluid intake for pregnancy or breastfeeding.